Process of making pigments.



UNITED STATES PATENT OFFICE.

THOMAS JOHN OSULLlVAN, LONDON, CANADA, ASS IGNOR TO'HELENA AMELIAOSULLIVAN, OF SAME PLACE.

PROCESS OF MAKING PI GMENTS.

SPECIFICATION forming part of Letters Patent No. 629,268, dated July 18,1899.

Application filed March 10, 1899- Serial No. 708,551. (No specimens.)

To aZZ whom it may concern.-

Be it known that I, THOMAS JOHN OSULLI- VAN, a subject of the Queen ofGreat Britain, residing at the city of London, in the county ofMiddlesex and Province of Ontario, Dominion of Canada, have invented anew and useful,

Process for Making Pigments,of which the following is a specification. AMy invention is in the nature of a new process for making dry pigment,which is designed to be afterward mixedwith oil to form a paint.

It consists in saturating sawdust witha solution of a salt of iron andthen drying and I 5 burningit,the residuum forming the pigment.

For the salt of iron I may use nitrate of iron, muriate of iron, sulfateof iron, phosphate of iron, or any other product obtained by treatingiron with an acid. The solution may vary widely in strength; butI find asolution of six to fiftyfive per cent. of the iron salt is best adaptedto my uses.

To make the paint, Itake a definite quantityof wood sawdust and saturateit with a solution of the iron salt. The strength of the solutiondetermines the different shades of paint, the less iron salt to a givenquantity of sawdust the darker will be the resulting pigment, andviceversa. After the sawdust has 0 been saturated with the solution itis dried and burned in direct contact with the air. For this purpose itis only necessary to place it in a wire basket, start a fire beneath itto when mixed with oil forms a very cheap and and its conversion into ared oxid of iron mixed with the ash of the cellulose and more or 5 lessunconsumed carbon. The physical aspect of the burned product is apowderor friable mass of a color varying from light red to dark brown,which forms a pigment which durable paint.

This pigment is very cheaply made, as the sawdust is practically a wastematerial and in burning furnishes the necessary heat to complete theoperation after being dried out. 5 5.

What I claim as the invention, and desire to secure by Letters Patent,is

The process of producing a pigment which consists in saturating sawdustwith a salt of iron and then drying and burning it substantially asshown and described.

THOMAS JOHN OSULLIVAN. v

